service discovery in ubiquitous and pervasive environments presented by knarig arabshian phd...
Post on 19-Dec-2015
222 Views
Preview:
TRANSCRIPT
Service Discovery in Service Discovery in Ubiquitous and Pervasive Ubiquitous and Pervasive EnvironmentsEnvironments
Presented by Knarig Arabshian
PhD candidacy exam October 26, 2004
OverviewOverview
IntroductionHistory of service discovery, challenges
ComponentsDescription, distribution, query
Existing systemsMainstream, ad-hoc, location aware, semantic, Internet-scale
http://www.cs.columbia.edu/~knarig/candidacy/candidacyList.html
What is service discovery?What is service discovery?
Provider ConsumerDirectory
Distribution Query
Service description
Service vs resource discovery
History History of resource discoveryof resource discovery
System Resource Example Remarks
RLP(1983)
IP Address of some host
Finding an internet gateway
Request is directed to IP or broadcast to subnet.
Whois(1985)
Users Domain names Centralized, Localized information
X.500(1988)
General User directory Distributed storage, Complexity (maintaining, populating and querying databases)
Archie(1992)
Files User information Automated (FTP) directory updates, regular expression query
WWW(1992)
Document Web pages Distributed, URL
[6] A comparison of internet resource discovery approaches, 1992[7] Resource location protocol, 1983
MotivationMotivationfor new service discovery protocolsfor new service discovery protocols
Static resource information (whois, RLP, X.500)
Automatic discovery of LAN network services (SLP, Jini, UPnP)
Automatic Automatically announce or register
service instead of manually entering information.
LAN services Printer, FAX machine, …
[8] Protocols for service discovery in dynamic and mobile networks, IJCR (Journal), 2002
MotivationMotivationfor new service discovery protocolsfor new service discovery protocols
Static resource information (whois, RLP, X.500)
Automatic discovery of LAN network services (SLP, Jini, UPnP)
Internet scale discovery (INS/Twine, Ninja)
Wide-area service discovery Multiple attributes Auto configured and rapid availability Automated discovery without user
input Policy support by agent Scalable
MotivationMotivationfor new service discovery protocolsfor new service discovery protocols
Static resource information (whois, RLP, X.500)
Automatic discovery of LAN network services (SLP, Jini, UPnP)
Internet scale discovery (INS/Twine, Ninja, CoolTown)
Ad hoc discovery without infrastructure (Konark, DEAPSpace)
Pervasive computing User intent Client thickness Cyber foraging (living off the
land) Context awareness Proactive vs transparent Ad hoc networks
Location aware discovery (Agents2Go, Splendor)
Semantic service discovery (Ronin, DReggie)
Me-services Personal and pervasive Semantic service discovery Dynamic service
composition Distributed trust
management Profile driven management Semantic web
Express meaning Knowledge representation using
ontologies Improving accuracy of web search Agents exchange ontology information
to perform service discovery[1] The semantic web, Scientific American, 2001[2] Pervasive computing: vision and challenges, IEEE personal communications, 2001[4] Me-services: a framework for secure and personalized discovery…, 2002
ComponentsComponents Directory
repository Centralized Distributed
Hierarchical Structured P2P Ad hoc
Service description Attribute/value Tree-like XML Ontologies (DAML)
Provider ConsumerDirectory
ComponentsComponents Announcement
Register Multicast/broadcast
Query/Service Access Syntax Ontology Programming
language dependency
Provider ConsumerDirectory
References for mainstream protocols:[9] The Service Location Protocol, IEEE Internet Computing, 1999[11] Jini architecture specification, Sun Microsystems, 2003[12] Understanding Universal Plug and Play white paper, Microsoft, 2000[13] Specification of the Bluetooth system, Bluetooth [14] Salutation architecture specification version 2.1, The Salutation Consortium, 1999
Mainstream protocolsMainstream protocolsJini Salutation SLP UPnP Bluetooth
Main Entities
LookupService, Client, Service
Salutation Manager, Transport Manager, Client Server
Directory Agent, Service Agent, User Agent
Control Point,Devices (Services)
SDP Client,SDP Server (or both)
Service Repository
Lookup Service
A set of SLMs
DA (directory agent)
None SDP Server
Service Announcement
Discovery/Join protocol
Registering with local SLM
Service Registration
Multicast advertisement
Not Supported
Access to Service
Service proxy object based on RMI
Service Session Management
Service type for discovered service
Invoking Action to service
Not Supported
Service Description
Interface type and attribute matching
Functional Unit and attributes within it
Service type and attribute matching
Description in XML
Attribute ID and Attribute Value
Mainstream protocolsMainstream protocolsJini Salutation SLP UPnP Bluetooth
Service Group
Group No Scope No Service Class
Event Notification
Remote Events
Availability Checking (periodic & automatic)
SLP extension for event notification
Service publishes event when state variable changes
Not Supported
OtherFeatures
Java-centric architecture
Transport independence
Authentication security feature
Automatic configuration
Services could be browsed from a hierarchy
Usage CNN and sprint Web/ Directory Servers, E-mail, Calendar, Collaboration Servers
Novell Netware
WinXP for gateways, Internet connectivity and NAT
Bluetooth access points, print adaptors,Palm OS bluetooth system
More protocols…More protocols…mSLP: mesh-enhanced SLPmSLP: mesh-enhanced SLP
Fully-meshed peering DA architecture with one or more scopes in common
Reliability Scalability Backward Compatibility-
extends DA Advertisement with a “mesh-enhanced” attribute
[10] mSLP – mesh enhanced SLP, ICCCN, 2000
More protocols…More protocols…UDDI: Universal Description, Discovery and UDDI: Universal Description, Discovery and IntegrationIntegration
UDDI specifications and schemas used to build discovery services on Internet
Provide consistent publishing interface Allow programmatic discovery of services Who: Sun, IBM, Microsoft partnership
[15] UDDI technical white paper, 2000
More Protocols…More Protocols…UDDI: Universal Description, Discovery and UDDI: Universal Description, Discovery and IntegrationIntegration
Business registry
contains yellow, white, green
pages
Consumers access services
by using the Programmer’s
API built on SOAP
Services described in XML
and published using Publisher’s
API
Design for ad hoc Design for ad hoc networksnetworks
KonarkDeapSpace
GSDAllia
No central directory service Limited use of network/device resources Reliability Pervasive Distributed
Design for ad hoc Design for ad hoc networksnetworks Main entities
Node acts as client+server Service announcement
Flooding On device join Periodically, delta announcement (Konark) Slotted (DEAPSpace uses slotted+periodic)
Cache advertisements TTL
Design for ad hoc Design for ad hoc networksnetworks Service description
What is described? service name, type, attribute, keywords,
properties and functions Service hierarchy - tree like structure (Konark,
GSD) Interface format, e.g., function prototype.
How is it described and stored? WSDL file (Konark) Data structures similar to ASN.1 (DEAPSpace)
Encoder/decoder Ontology: DAML+OIL (GSD)
Design for ad hoc Design for ad hoc networksnetworks Access to the service
RPC SOAP/HTTP (Konark) Specific Interface, e.g., function prototype
Encoder/decoder (DEAPSpace) Query formation
Path based or syntax based Request routing
Policy based (Allia) Group based (GSD)
ContributionsContributionsKonark DEAPSpace GSD Allia
Service Description
WSDL, hierarchy of services
Data structures (encoder/decoder)
DAML+OIL N/A
Service Announcement
Delta gossip protocol
Slotted+periodic broadcast
Broadcast (broadcastID)
Policy based alliance of nearby nodes
Access to Service
SOAP/HTTP; path or syntax based query
Interface N/D N/D
Other Remarks Intelligently routes to the service groups
Provides a policy based framework (Advertisement, Cache and Forwarding Managers)
[17] Konark – a service discovery and delivery protocol for ad hoc networks, WCNC, 2003[18] DEAPspace – transient ad hoc networking of pervasive devices, Computer Networks, 2001[19] GSD: a novel group-based service discovery for MANETS, MWCN, 2002[20] Allia: alliance-based service discovery for ad-hoc environments, WMC, 2002
Design for semantic Design for semantic ontologiesontologies
Find me the best cab
service…
Ronin Agent FrameworkDReggie
Use of semantic ontologies Inexact/exact querying More powerful reasoning engines and AI
tools Enhancing current service location protocols
ContributionsContributionsRonin Agent Framework Built on top of Jini
Jini Prolog engine Agent-oriented
development Java classes and interfaces
printing service, restaurant service
Communicate with other agents using Agent Communication Language
Agent deputy Mediates agent
communication Represents owner agent in
the network Located in the Jini Lookup
Service
Dreggie for M-commerce
Enhance Jini Matching mechanism of
Jini’s LookupService Prolog reasoning engine
used for matching Service registration along
with interface registration
Services register with DAML description and interface
DAML gives hierarchical description of services
[21] Dynamic service discovery for mobile computing, BSJCC (Journal), 2001[22] Dreggie: semantic service discovery for M-commerce applications, 2001
Location-aware service Location-aware service discoverydiscovery
Where is the closest Italian restaurantto me?• Location sensing• Nomadic users• Handy devices
CoolTown,Splendor,
Agents2Go
CoolTownCoolTown Every service (e.g., printer) has a web server, and a tag. Users walk in and receive URL from tag beacons Connect to the URL which describes the service and can
invokes it Place manager maintains resources in a place, with web
interface (HTML and XML) Resources can be grouped. Also acts as a resolver for some places
SplendorSplendor Tag-based location aware
Tag label location and people Proxies
Enhanced security Service management (registration, security)
Bootstrapping using multicast
Trusted servers
managing services
Area 3
Area 2
Agents2GoAgents2Go
Agents2Go Server
PalmApp (with CDPD modem)
Restaurant agentor other services
Locator
Brokers
Cell tower
Location identified by cell tower id
Initial query form
User query
User query
Maps geographic area to broker
register
ContributionsContributions
Attach web URL to services and periodically broadcast (CoolTown)
Intermediate trusted proxy for security and service management (Splendor)
Localized brokers store services in the location and are mapped to based on the user location (Agent2Go)
[23] Agents2Go: an infrastructure for location-dependent service discovery, 2001[24] Splendor: a secure, private, location-aware service discovery protocol, 2003[25] A web-based nomadic computing system, Computer Networks, 2001
Internet-scale discoveryInternet-scale discovery
INS/Twine,Ninja/SDS,
WSPDS
Construct scalable, robust services Huge throughput demands and availability Interoperability Efficiency Fault tolerance
INS/TwineINS/Twine Uses Chord
structured peer to peer system
Lookup in Log(N) Service Propagation
Resource state changes, update is propagated
Periodic refreshing of resource information
edge resolvers attached to clients update frequently
Internal resolvers infrequently
root
traffic
subjectres
camera
modelman
AModelACompany
Resource is a camera, manufactured by ACompany and filming traffic.
Distributed hash table (Chord). KeyRouter maps to Chord.
StrandMapperHash(strand)
resolver
[30] INS/Twine: a scalable p2p architecture for intentional resource discovery, 2002
NinjaNinjaSecure Service Discovery
Service (SDS) Uses XML to encode
service descriptions Certificate Authority
and Capability Managers for security
Servers dynamically organize themselves into hierarchies for scalability
Filters query upwards to avoid overloading one node (Bloom filter)
Services running on clusters of workstations
A chain across proxies and bases to find better service
Heterogeneous devices and sensors
Stateless and soft-state proxy
Distributed data structures
[28] The ninja architecture for robust Internet-scale systems and services, JCN, 2001[27] An architecture for a secure service discovery service, MobiCom, 1999
Multi-tier ubiquitous Multi-tier ubiquitous service discovery protocolservice discovery protocol
Context attributes provided by services
Distance to server Server load Service channel
Attribute-value pair service description
Localized Service Propagation
propagate upward with attenuation factor of service attributes
Query Routing Overlay hierarchy
Global Services Registry-
gateway to global network
Brokering Agent-
recommends
appropriate service
Domain Hierarchy
Global Services
[26] A multi-tier ubiquitous service discovery protocol, Mobisys, 2003
WSPDS: Web Services P2P WSPDS: Web Services P2P Discovery ServiceDiscovery Service Servent: Server/Client DAML ontology for service
description Querical data network
Probabilistic flooding Each node defined by content Node links to other nodes of smiliar
content Semantic matching algorithm used to
choose neighbor[29] WSPDS: web services p2p discovery service, ISWS, 2004
ContributionsContributions INS/Twine: structured P2P lookup
on strands Ninja/SDS: query filtering and
service aggregation Multi-tier Ubiquitous SDP: context
attributes, hierarchical, localized service propagation
WSPDS: QDN, DAML for service description
ConclusionsConclusions Service discovery for different
scenarios in ubiquitous and pervasive environments: ad-hoc, location-aware, semantic and Internet-scale, and combinations of these
Tackle problems in service distribution, query and description
Not much work done in semantic service discovery
ReferencesReferences1. T. Berners-Lee, J. Hendler, and O. Lassila, The Semantic Web, Scientific American , May 2001 2. M. Satyanarayanan, Pervasive Computing: Vision and Challenges, IEEE Personal Communications , August 2001. 3. M. Weiser, The computer for the twenty-first century Scientific American, pp 94-103, September 1992 4. Anupam Joshi, Tim Finin, and Yelena Yesha,
Me-Services: A Framework for Secure and Personalized Discovery, Composition and Management of Services in Pervasive Environments, in Web Services, E-Business, and the Semantic Web, C. Bussler, R. Hull, S. McIlraith, M.E. Orlowska, B. Pernici, J. Yang (Eds.), LNCS 2512, p. 248 ff., Springer, ISBN:3540001980, December 2002
5. J. Rosenberg, E. Guttman, R. Moats, H. Schulzrinne, WASRV Architectural Principles Internet Draft, Internet Engineering Task Force, Feb. 1998. Work in progress.
6. Michael F. Schwartz, Alan Emtage, Brewster Kahle, and B. Clifford Newman. A comparison of internet resource discovery approaches, Computing Systems, 5(4):466-493, Fall 1992.
7. M. Accetta, Resource Location Protocol RFC 887, Internet Engineering Task Force, December 1983. 8. C. Lee, S. Helal, Protocols for Service Discovery in Dynamic and Mobile Networks, International Journal of
Computer Research, Volume 11, pp 1-12, 2002 9. Erik Guttman, The Service Location Protocol, IEEE Internet Computing July 1999. 10. Weibin Zhao, Henning Schulzrinne and Erik Guttman, "mSLP - Mesh-enhanced Service Location Protocol",
International Conference on Computer Communications and Networks (ICCCN'00), October, 2000. 11. Jini Architecture Specification, Sun Microsystems, June 2003 12. Understanding Universal Plug and Play White Paper, Microsoft Corporation, June 2000. 13. Specification of the Bluetooth System, Bluetooth (www.bluetooth.org), pp 113-156 14. Salutation Architecture Specification Version 2.1, The Salutation Consortium, 1999 15. UDDI Technical White Paper, UDDI (Universal Description, Discovery and Integration), September 2000. 16. A. Gulbrandsen, P. Vixie, L. Esibov, A DNS RR for specifying the location of services (DNS SRV) RFC 2782, Internet
Engineering Task Force, February 2000.
ReferencesReferences17. S. Helal, N. Desai, V. Verma and C. Lee, Konark--A Service Discovery and Delivery Protocol for Ad-hoc Networks, Proceedings of the Third
IEEE Conference on Wireless Communication Networks (WCNC), New Orleans, March 2003. 18. R. Hermann, D. Husemann, M. Moser, M. Nidd, C. Rohner, A. Schade, DEAPspace--Transient ad hoc networking of pervasive devices,
Computer Networks Volume 35 pp 411-428, 2001 19. D. Chakraborty, A. Joshi, , GSD: A Novel Group-based Service Discovery Protocol for MANETS, 4th IEEE Conference on Mobile and
Wireless Communications Networks (MWCN 2002). Stockholm. Sweden. September. 2002 20. Olga Ratsimor, Dipanjan Chakraborty, Sovrin Tolia, Deepali Kushraj, Anugeetha Kunjithapatham, Gaurav Gupta, Anupam Joshi, Timothy
Finin, Allia: Alliance-based Service Discovery for Ad-Hoc Environments, Second ACM International Workshop on Mobile Commerce, in conjunction with Mobicom 2002, Sep 28, 2002, Atlanta GA, USA
21. H. Chen, A. Joshi, T. Finin. Dynamic Service Discovery for Mobile Computing: Intelligent Agents Meet Jini in the Aether, Baltzer Science Journal on Cluster Computing, Vol. 4, No. 4, March 2001
22. D. Chakraborty, F. Perich, S. Avancha, and A. Joshi. DReggie: Semantic Service Discovery for M-Commerce Applications In Workshop on Reliable and Secure Applications in Mobile Environment, Symposium on Reliable Distributed Systems, October 2001.
23. O. Ratsimor, V. Korolev, A. Joshi, T. Finin. Agents2Go: An Infrastructure for Location-Dependent Service Discovery in The Mobile Electronic Commerce Environment ACM Mobile Commerce Workshop, July, 2001
24. F. Zhu, M. Mutka, and L. Ni, Splendor: A Secure, Private, and Location-aware Service Discovery Protocol Supporting Mobile Services 1st IEEE Annual Conference on Pervasive Computing and Communications, IEEE Computer Society Press, Fort Worth, Texas, 2003
25. T. Kindberg and J. Barton, A Web-based nomadic computing system, Computer Networks, Esevier. Vol 35, No. 4, March 2001, 443-456 26. C. Lee and A. Helal, A Multi-tier Ubiquitous Service Discovery Protocol First ACM International Conference on Mobile Systems and
Applications (Mobisys), May 2003 27. S.E. Czerwinski, B. Zhao, T. Hodes, A. Joseph, and R. Katz, An Architecture for a Secure Service Discovery Service, Fifth Annual
International Conference on Mobile Computing and Networks (MobiCom '99), Seattle, WA, August 1999, pp. 24-35 28. S. D. Gribble, M. Welsh, R. von Behren, E. A. Brewer, D. Culler, N. Borisov, S. Czerwinski, R. Gummadi, J. Hill, A. Joseph, R. H. Katz, Z. M.
Mao, S. Ross, and B. Zhao, The Ninja architecture for robust Internet-scale systems and services, Journal of Computer Networks, vol. 35, no. 4, March 2001.
29. Farnoush Banaei-Kashani, Ching-Chien Chen, Cyrus Shahabi, WSPDS: Web Services Peer-to-peer Discovery Service , International Symposium on Web Services and Applications(ISWS'04) , Las Vegas, Nevada, USA, June, 2004
30. M. Balazinska, H. Balakrishnan, D. Karger, INS/Twine: A Scalable Peer-to-Peer Architecture for Intentional Resource Discovery, International Conference on Pervasive Computing August 2002
top related